The present disclosure relates to an absorber element for solar high-temperature heat generation, the absorber element having a light focusing element unit and an outer tube composed of a translucent material, and an absorber which is arranged in the outer tube and to which the solar rays are passed by the light focusing element. The present disclosure also relates to a method for producing the absorber element.
Absorber elements are generally known. In solar-thermal power stations, the radiation energy from the sun is concentrated by mirror systems, preferably with readjustment, and is used for heating a heat carrier medium. In one generally known design, the heat carrier medium flows through long absorber tubes, which are arranged at the focus of parabolic groove collectors.
Instead of using reflecting systems, the radiation energy can also be concentrated by using refracting systems (convergent lenses). One example of a linearly optically concentrating system such as this is disclosed in U.S. Pat. No. 4,287,881, dated 8 Sep. 1981.
Solar collectors, in which the actual absorber is surrounded by elements which reflect the radiation back to it, are disclosed, for example, in French Patent 555 420, U.S. Pat. Nos. 4,300,538, 4,440,155, 4,512,335 and German Patents 27 57 155 and 30 20 310.
One problem with solar high-temperature heat generation is the heat losses that result from radiation emitted by the absorber tube. Owing to the high temperature, these heat losses are considerable. In order to reduce the heat losses, it is generally known for the actual absorber tube to be arranged in an outer tube. Although this reduces the heat losses, they are, however, still sufficiently high that the efficiency of solar high-temperature heat generation remains well below the theoretically achievable level.